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Particulate Matter: Widespread and Deadly

Particulate matter (PM) is the most widespread air pollutant in the country, and it can be deadly. Airborne particulates, especially the smallest, contribute to the four leading causes of death in the United States: heart disease, cancer, chronic lower respiratory diseases, and stroke. PM also contributes to preterm and low birth weight babies, irregular heartbeat and aggravated asthma, as well as other dangerous health effects. Because of PM’s prevalence and its high levels of toxicity, the Environmental Protection Agency (EPA) is currently updating its standards for limits on PM in the atmosphere.

Rather than being a specific substance, PM is a mixture of airborne particles, both solid and liquid, classified by size. “Coarse” particulates are those with a diameter larger than 2.5 micrometers and smaller than or equal to10 micrometers; these particles are known as PM10. “Fine” particulates have a diameter of 2.5 microns or smaller. By comparison, the average human hair is about 70 micrometers in diameter – 30 times larger than the largest fine particle. Coal-fired power plants, industries, diesel vehicles and cars are responsible for most of the fine PM in the country

Whether fine or coarse, PM can be inhaled and can pass through the throat and nose and enter the lungs. The finest particles travel deeply into the lung where they trigger disease-producing processes including inflammation, oxidative stress, and resulting tissue damage. Particulates with the smallest diameter can also cross nasal membranes into the brain, where evidence suggests that they trigger inflammatory responses and the creation of reactive oxygen species that induce oxidative stress that leads to cell death.

What harm is being caused by PM exposure, and what populations are most vulnerable? Are the proposed EPA standards sufficient to protect public health? This month’s Environmental Health Policy Institute proposes to answer those questions. The answers have an important bearing on the health of Americans from coast to coast.

Comments

Jack C. Westman, M.D., M.S, said ..

Fossil Fuels→Air pollution→Global warming
Why is the public focus on global warming without mentioning air pollution as a contributing cause? Why is air pollution taken out of the equation: Fossil fuels→Air pollution→Global warming?
The fossil fuel industries benefit from taking the focus off air pollution and placing it on global warming. Then any research that questions the human influence on global warming, however biased, can be cited as evidence that fossil fuels are not harmful. All that matters is that we are in the warming trend of the last Ice Age, which opens up new areas for fossil fuel exploration.
In fact, a rigorous, peer reviewed analysis, The Benefits and Costs of the Clean Air Act from 1990 to 2020, conducted by the Environmental Protection Agency, found that, unless undermined by current efforts to weaken or repeal the Clean Air Act, the benefits of the Act will reach about $2.0 trillion in 2020 at an estimated cost of about $65 billion. The EPA estimates that by 2020 cleaner air will prevent 230,000 premature deaths.
Our air is polluted by more than fossil fuel produced greenhouse gases that clearly contribute to global warming. Fossil fuels also pollute our air with soot, mercury, arsenic, lead, ozone, nitrogen oxides, carbon monoxide, sulfur dioxide, and toxic chemicals that contribute to lung and heart diseases, cancer, developmental disabilities, and adverse environmental effects, including acid rain and mercury-polluted water.
The fossil fuel industries also benefit from minimizing awareness of air pollution in the United States by the way in which the air quality index is reported to the public.
Most newspapers carry daily reports on air quality. Our air is continually polluted, but pollution is considered acceptable unless there is an immediate and observable effect on our health. The air quality is rated as “good” if the pollution level is mild: 50 or below; moderate if 50-100; and unhealthy if 101-150. Public concern is raised only on high ozone days when the air is rated as “unhealthy.” In fact, moderate, and even mild for some persons, levels of pollution harm health.
Climate models predict that heat waves will increase in intensity, frequency, and duration over the course of this century. This trend will increase air quality problems across the United States and accelerate the formation of ground-level ozone. The health problems associated with exposure to extreme and prolonged heat—heat cramps, fainting, exhaustion, and stroke—will become increasingly common.
As people adapt to warmer temperatures, increased energy use to power air conditioners puts even greater amounts of pollutants into the air.
Air pollution in the rest of the world, especially China, contributes to our air pollution. Although reduced during the 2008 Beijing Olympics by shutting down industries and motor vehicle traffic, videos of the games reveal what we would regard as absolutely intolerable air pollution in the United States. This is why China now is stressing the reduction of air pollution and the manufacture of green energy sources.
We must not be diverted from awareness that air pollution is at unacceptable levels now by arguments over global warming and the costs of cleaning up our air that actually are small compared to the immense health care costs of air pollution. An estimated $281 billion in health expenditures would be saved every year by reducing costs from diseases and premature deaths.
Even with the Clean Air Act, the United States has failed to lead the world in reducing air pollution that causes global warming. For example, the Environmental Protection Agency is proposing inadequate air particle standards now. Medical and public health professionals call for an annual limit of 11 micrograms of soot per cubic meter.
Our personal and environmental health is being affected by polluted air here and now.
Action to reduce air pollution by industries and motor vehicles is urgently needed now in the United States and in the rest of the world.